translation: Add Python and Java code for EN version (#1345)

* Add the intial translation of code of all the languages

* test

* revert

* Remove

* Add Python and Java code for EN version

en/codes/python/chapter_searching/binary_search.py

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+"""
+File: binary_search.py
+Created Time: 2022-11-26
+Author: timi (xisunyy@163.com)
+"""
+
+
+def binary_search(nums: list[int], target: int) -> int:
+    """Binary search (double closed interval)"""
+    # Initialize double closed interval [0, n-1], i.e., i, j point to the first element and last element of the array respectively
+    i, j = 0, len(nums) - 1
+    # Loop until the search interval is empty (when i > j, it is empty)
+    while i <= j:
+        # Theoretically, Python's numbers can be infinitely large (depending on memory size), so there is no need to consider large number overflow
+        m = (i + j) // 2  # Calculate midpoint index m
+        if nums[m] < target:
+            i = m + 1  # This situation indicates that target is in the interval [m+1, j]
+        elif nums[m] > target:
+            j = m - 1  # This situation indicates that target is in the interval [i, m-1]
+        else:
+            return m  # Found the target element, thus return its index
+    return -1  # Did not find the target element, thus return -1
+
+
+def binary_search_lcro(nums: list[int], target: int) -> int:
+    """Binary search (left closed right open interval)"""
+    # Initialize left closed right open interval [0, n), i.e., i, j point to the first element and the last element +1 of the array respectively
+    i, j = 0, len(nums)
+    # Loop until the search interval is empty (when i = j, it is empty)
+    while i < j:
+        m = (i + j) // 2  # Calculate midpoint index m
+        if nums[m] < target:
+            i = m + 1  # This situation indicates that target is in the interval [m+1, j)
+        elif nums[m] > target:
+            j = m  # This situation indicates that target is in the interval [i, m)
+        else:
+            return m  # Found the target element, thus return its index
+    return -1  # Did not find the target element, thus return -1
+
+
+"""Driver Code"""
+if __name__ == "__main__":
+    target = 6
+    nums = [1, 3, 6, 8, 12, 15, 23, 26, 31, 35]
+
+    # Binary search (double closed interval)
+    index = binary_search(nums, target)
+    print("Index of target element 6 =", index)
+
+    # Binary search (left closed right open interval)
+    index = binary_search_lcro(nums, target)
+    print("Index of target element 6 =", index)

en/codes/python/chapter_searching/binary_search_edge.py

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+"""
+File: binary_search_edge.py
+Created Time: 2023-08-04
+Author: krahets (krahets@163.com)
+"""
+
+import sys
+from pathlib import Path
+
+sys.path.append(str(Path(__file__).parent.parent))
+from binary_search_insertion import binary_search_insertion
+
+
+def binary_search_left_edge(nums: list[int], target: int) -> int:
+    """Binary search for the leftmost target"""
+    # Equivalent to finding the insertion point of target
+    i = binary_search_insertion(nums, target)
+    # Did not find target, thus return -1
+    if i == len(nums) or nums[i] != target:
+        return -1
+    # Found target, return index i
+    return i
+
+
+def binary_search_right_edge(nums: list[int], target: int) -> int:
+    """Binary search for the rightmost target"""
+    # Convert to finding the leftmost target + 1
+    i = binary_search_insertion(nums, target + 1)
+    # j points to the rightmost target, i points to the first element greater than target
+    j = i - 1
+    # Did not find target, thus return -1
+    if j == -1 or nums[j] != target:
+        return -1
+    # Found target, return index j
+    return j
+
+
+"""Driver Code"""
+if __name__ == "__main__":
+    # Array with duplicate elements
+    nums = [1, 3, 6, 6, 6, 6, 6, 10, 12, 15]
+    print(f"\nArray nums = {nums}")
+
+    # Binary search for left and right boundaries
+    for target in [6, 7]:
+        index = binary_search_left_edge(nums, target)
+        print(f"The index of the leftmost element {target} is {index}")
+        index = binary_search_right_edge(nums, target)
+        print(f"The index of the rightmost element {target} is {index}")

en/codes/python/chapter_searching/binary_search_insertion.py

@@ -0,0 +1,54 @@
+"""
+File: binary_search_insertion.py
+Created Time: 2023-08-04
+Author: krahets (krahets@163.com)
+"""
+
+
+def binary_search_insertion_simple(nums: list[int], target: int) -> int:
+    """Binary search for insertion point (no duplicate elements)"""
+    i, j = 0, len(nums) - 1  # Initialize double closed interval [0, n-1]
+    while i <= j:
+        m = (i + j) // 2  # Calculate midpoint index m
+        if nums[m] < target:
+            i = m + 1  # Target is in interval [m+1, j]
+        elif nums[m] > target:
+            j = m - 1  # Target is in interval [i, m-1]
+        else:
+            return m  # Found target, return insertion point m
+    # Did not find target, return insertion point i
+    return i
+
+
+def binary_search_insertion(nums: list[int], target: int) -> int:
+    """Binary search for insertion point (with duplicate elements)"""
+    i, j = 0, len(nums) - 1  # Initialize double closed interval [0, n-1]
+    while i <= j:
+        m = (i + j) // 2  # Calculate midpoint index m
+        if nums[m] < target:
+            i = m + 1  # Target is in interval [m+1, j]
+        elif nums[m] > target:
+            j = m - 1  # Target is in interval [i, m-1]
+        else:
+            j = m - 1  # First element less than target is in interval [i, m-1]
+    # Return insertion point i
+    return i
+
+
+"""Driver Code"""
+if __name__ == "__main__":
+    # Array without duplicate elements
+    nums = [1, 3, 6, 8, 12, 15, 23, 26, 31, 35]
+    print(f"\nArray nums = {nums}")
+    # Binary search for insertion point
+    for target in [6, 9]:
+        index = binary_search_insertion_simple(nums, target)
+        print(f"Element {target}'s insertion point index is {index}")
+
+    # Array with duplicate elements
+    nums = [1, 3, 6, 6, 6, 6, 6, 10, 12, 15]
+    print(f"\nArray nums = {nums}")
+    # Binary search for insertion point
+    for target in [2, 6, 20]:
+        index = binary_search_insertion(nums, target)
+        print(f"Element {target}'s insertion point index is {index}")

en/codes/python/chapter_searching/hashing_search.py

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+"""
+File: hashing_search.py
+Created Time: 2022-11-26
+Author: timi (xisunyy@163.com)
+"""
+
+import sys
+from pathlib import Path
+
+sys.path.append(str(Path(__file__).parent.parent))
+from modules import ListNode, list_to_linked_list
+
+
+def hashing_search_array(hmap: dict[int, int], target: int) -> int:
+    """Hash search (array)"""
+    # Hash table's key: target element, value: index
+    # If the hash table does not contain this key, return -1
+    return hmap.get(target, -1)
+
+
+def hashing_search_linkedlist(
+    hmap: dict[int, ListNode], target: int
+) -> ListNode | None:
+    """Hash search (linked list)"""
+    # Hash table's key: target element, value: node object
+    # If the hash table does not contain this key, return None
+    return hmap.get(target, None)
+
+
+"""Driver Code"""
+if __name__ == "__main__":
+    target = 3
+
+    # Hash search (array)
+    nums = [1, 5, 3, 2, 4, 7, 5, 9, 10, 8]
+    # Initialize hash table
+    map0 = dict[int, int]()
+    for i in range(len(nums)):
+        map0[nums[i]] = i  # key: element, value: index
+    index: int = hashing_search_array(map0, target)
+    print("Index of target element 3 =", index)
+
+    # Hash search (linked list)
+    head: ListNode = list_to_linked_list(nums)
+    # Initialize hash table
+    map1 = dict[int, ListNode]()
+    while head:
+        map1[head.val] = head  # key: node value, value: node
+        head = head.next
+    node: ListNode = hashing_search_linkedlist(map1, target)
+    print("Target node value 3's corresponding node object is", node)

en/codes/python/chapter_searching/linear_search.py

@@ -0,0 +1,45 @@
+"""
+File: linear_search.py
+Created Time: 2022-11-26
+Author: timi (xisunyy@163.com)
+"""
+
+import sys
+from pathlib import Path
+
+sys.path.append(str(Path(__file__).parent.parent))
+from modules import ListNode, list_to_linked_list
+
+
+def linear_search_array(nums: list[int], target: int) -> int:
+    """Linear search (array)"""
+    # Traverse array
+    for i in range(len(nums)):
+        if nums[i] == target:  # Found the target element, thus return its index
+            return i
+    return -1  # Did not find the target element, thus return -1
+
+
+def linear_search_linkedlist(head: ListNode, target: int) -> ListNode | None:
+    """Linear search (linked list)"""
+    # Traverse the list
+    while head:
+        if head.val == target:  # Found the target node, return it
+            return head
+        head = head.next
+    return None  # Did not find the target node, thus return None
+
+
+"""Driver Code"""
+if __name__ == "__main__":
+    target = 3
+
+    # Perform linear search in array
+    nums = [1, 5, 3, 2, 4, 7, 5, 9, 10, 8]
+    index: int = linear_search_array(nums, target)
+    print("Index of target element 3 =", index)
+
+    # Perform linear search in linked list
+    head: ListNode = list_to_linked_list(nums)
+    node: ListNode | None = linear_search_linkedlist(head, target)
+    print("Target node value 3's corresponding node object is", node)

en/codes/python/chapter_searching/two_sum.py

@@ -0,0 +1,42 @@
+"""
+File: two_sum.py
+Created Time: 2022-11-25
+Author: krahets (krahets@163.com)
+"""
+
+
+def two_sum_brute_force(nums: list[int], target: int) -> list[int]:
+    """Method one: Brute force enumeration"""
+    # Two-layer loop, time complexity is O(n^2)
+    for i in range(len(nums) - 1):
+        for j in range(i + 1, len(nums)):
+            if nums[i] + nums[j] == target:
+                return [i, j]
+    return []
+
+
+def two_sum_hash_table(nums: list[int], target: int) -> list[int]:
+    """Method two: Auxiliary hash table"""
+    # Auxiliary hash table, space complexity is O(n)
+    dic = {}
+    # Single-layer loop, time complexity is O(n)
+    for i in range(len(nums)):
+        if target - nums[i] in dic:
+            return [dic[target - nums[i]], i]
+        dic[nums[i]] = i
+    return []
+
+
+"""Driver Code"""
+if __name__ == "__main__":
+    # ======= Test Case =======
+    nums = [2, 7, 11, 15]
+    target = 13
+
+    # ====== Driver Code ======
+    # Method one
+    res: list[int] = two_sum_brute_force(nums, target)
+    print("Method one res =", res)
+    # Method two
+    res: list[int] = two_sum_hash_table(nums, target)
+    print("Method two res =", res)